3rd year tutorial 1

Question 1

define relative risk

Answer 1

a measure of the strength of an association between a suspected risk factor and a disease

Question 2

Give examples of sources of epidemiological data

Answer 2

Mortality data
Hospital activity stats
Reproductive health stats
Cancer stats
Accident stats
General practice morbidity
health and household surveys
Social security stats
Drug misuse databases
Expenditure data from NHS

Question 3

What is a descriptive study?

Answer 3

Observation of a disease; looks at time, place and person

Question 4

What are the uses of descriptive studies?

Answer 4

identify emerging problems
assess effectiveness of preventative measures e.g screening programmes
assess need for services
hypothesise about disease aetiologu

Question 5

Give three types of analytical studies

Answer 5

cross-sectional
case-control
cohort

Question 6

What type of trial is most commonly used?

Answer 6

randomised control trial

Question 7

What features must be considered when interpreting results?

Answer 7

Standardisation
Standardised mortality ratio
Quality of data
Case definition
Coding/classification
Ascertainment (is the data complete?)

Question 8

Give four types of bias

Answer 8

Selection bias
Information bias
Follow up bias
Systematic error

Question 9

What is the criteria for causality? Which one is essential?

Answer 9

Temporality - exposure occurs before disease
Strength of association (eg relative risk)
Consistency
Specificity
Biological gradient
Biological plausability 
Coherence
Analogy
Experiment (rarely possible in humans)

Question 10

Define confounding factors and give examples

Answer 10

Factors which are associated with both the disease and the exposure under investigation

• age
• sex
• social class

Question 11

What is an audit?

Answer 11

Systematic review o care against explicit criteria/guidelines and the implementation of change in order to improve the quality of care